Automatic die feeder



June 25, 1957 A. L. CAREY 2,797,087

. AUTOMATIC DIE FEEDER Filed Feb. 23, 1954 5 Sheets-Sheet 1 INVENTOR.

June 25, 1957 A. L. CAREY 2,797,087 AUTOMATIC DIE FEEDER Filed Feb. 23, 1954 '-5 Sheets-Sheet; 2

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INVENTOR. 4L5ET 4. c'ApeEY June 25, 1957 A. L. CAREY 2,797,037

AUTOMATIC DIE FEEDER Filed Feb. 25, 1954 5 Sheets-Sheet s I w f/y. 6 mmvrozc 4454? 4. CAFE) BY Aw A. L. CAREY AUTOMATIC DIE FEEDER June 25; 1957 5 Sheets-Sheet 4 Filed Feb. 25, 1954 INVENTOR.

ALBf QT L. 6/9/95) June 25, 1957 A. L. CA EY 239mm 7 AUTOMATIC DIE- FEEDER" Filed Feb. 25. 1954 5 Sheets-Shet 5 INVENTOR. 14455197 4. c e-Y 2,797,037 Patented June 25, 1957 ice nited States I Patent Ofi 2,797,087 AUTOMATIC DIE FEEDER Albert L. Carey, Sturgis, Mich assignor to Kirsch Company, Sturgis, Mich, a corporation of Michigan Application February 23, 1954, Serial No. 411,945

Claims. (Cl. 271-24) This invention relates in general to a mechanism for advancing elongated stock between the dies of a punch press and more particularly to a type thereof wherein such advancement is positively timed with respect to the movement of one of the dies toward the other.

In the punching of thin gauge sheet metal, that is, sheet metal which is too flexible to be reliably pushed through the dies, the normal practice, where the waste portion thereof constitutes a continuous web, is to pull the sheet through the dies by suitable means acting on the waste web. However, in operations where there is no continuous waste web, as in the making of parts where the punched sheet is cut into pieces which pieces are the finished parts, and the sheet is still too flexible to push through the dies, there are, and have long been, serious problems. Hand feeding has been used and this has resulted in (1) waste due to inaccurate operation, (2) excessive cost due to manual feeding, (3) need for highly skilled operators, and (4) dangers of hand feeding consistent with full utilization of the stock. Some feeding is done by shoes or rollers which intermittently engage and advance the stock in a jerky, and often harmful, manner and this also is normally unsatisfactory. This is particularly true Where a progressive die is being used in combination with a shear and the need for accuracy is great.

Accordingly, a primary object of this invention is the provision of a mechanism or device whereby elongated stock, as sheet material, can be automatically and accurately advanced between the dies of a punch press while overcoming the above problems encountered in present method of feeding such stock.

A further object of this invention is the provision of a mechanism, as aforesaid, which can be used alternatively to feed stock between a pair of spaced operations, even where one of said operations is a shearing operation.

A further object of the invention is to provide a device, as aforesaid, which can be used on either the supply or discharge end of a die, but which is particularly adaptable to use intermediate a pair of dies and a shear.

A further object of the invention is to provide a device, as aforesaid, which will move flexible stock without the use of longitudinally movable parts.

A further object of the invention is to provide a device, as aforesaid, which can be readily adjusted to effect feeding at any desired part of the die operating cycle and, when so adjusted, can then be positively locked in position.

A further object of this invention is the provision of a mechanism, as aforesaid, which operates automatically in timed relationship to movement of the movable die, and which operates accurately, efficiently and inexpensively.

A further object of this invention is the provision of a mechanism, as aforesaid, which is easily adaptable to various thicknesses of stock being fed and Whose basic elements can be applied in substance to a wide variety of related applications without change save in size and Strength.

Other objects of this invention will become apparent to persons acquainted with this type of equipment upon reading the following specification and examining the accompanying drawings, in which:

Figure 1 is a partially broken side elevation view of a combination punch press and shear incorporating my invention.

Figure 2 is a sectional view substantially as taken along the line II-II of Figure 1.

Figure 3 is a sectional view taken along the line III-III of Figure 2.

Figure 4 is a sectional view taken along the line IVIV of Figure 2.

Figure 5 is a sectional view substantially as taken along the line V--V of Figure 2.

Figure 6 is a sectional view substantially as taken along the line VI-Vl of Figure 2.

Figure 7 is a sectional view substantially as taken along the line VII-VII of Figure 1.

Figure 8 is a sectional view substantially as taken along the line VIII-VIII of Figure 2.

Figure 9 is an enlarged fragment of Figure 2 disclosing the left actuating lever.

In general In meeting those objects set forth above, as well as others incidental thereto, 1 have provided, in this particular embodiment of my invention, a mechanism having a pair of tangentially adjacent, parallel rolls, one of said rolls being located directly above the other. The lower roll is directly connected to a source of constant torque and rotatably supported by means fixed with respect to the lower stationary die of a conventional punch press. Said rolls are interconnected for substantially equal and simultaneous countenrotation. Positive means are provided for interrupting and stopping the rotation of said rolls for a preselected period of time. Progression of the work through successive working stations is thereby positively controlled within very close limits by said positive means without altering the application of said torque.

The upper roll is rotatably supported by means vertically movable toward and away from said lower roll. Actuation means, operable by the upper die of said punch press, is provided for eifecting vertical movement of said upper roll when said upper die is moved with respect to said lower die. This permits normal and conventional operation of the aligning pins of the dies just before enga-gement of the dies.

For convenience in description the terms upper, lower and derivatives thereof will be used herein with reference to the invention and parts associated therewith as appearing in Figures 1 and 2. The terms front and rear or entry and exit and derivatives thereof will be used with respect to the rightward and leftward ends, respectively, of the machine as appearing in Figure 1. The terms left, right and derivatives thereof will be used with reference to the machine as appearing in Figure 2, which is a view taken from entry end thereof.

Construction As shown in Figures 1 and 2, the feed mechanism 10,

to which this invention relates, is disclosed in conjunction with a punch press 11 of a conventional type having a movable upper die bed 12 which is vertically reciprocated by conventional means, such as the crank shaft 13 in the punch press head 14. Said punch press 11 has a lower stationary die bed 15 anchored in a conventional manner, not shown.

In this particular embodiment, a combination punching and shearing operation is conducted by the punch press 11 on a piece of thin sheet stock 16. Said sheet stock passes between the upper and lower dies 17 and 18, re-

spectively, at the front end of the die beds, thence through the feed mechanism and finally through the shear 19 which cuts the sheet stock into predetermined lengths. The dies 17 and 18' are of the progressive type in thisparticular embodiment, and have alignment means, as pins (not shown), for aligning the stock 16 in a conventional manner. I

As shown generally in Figure 2, the feed mechanism 10 includes a lower, driving roll 21 and an upper driven roll 22 parallel with, and tangentially adjacent to, said lower roll. Said lower roll- 21 is rotatably supported near its opposite ends in the bearings 23 and 24, which bearings are in turn supported in the left and rightbearing supports 25 and 26 (Figures 2, 7 and 8). Said bearin'gssup' ports are mounted upon the lower die b'ed' I5. The leftward end of the lower roll 21 is directly connected by means ofthe coupling 27 to a source 28 of constant torque mounted upon the motor bracket 29 which is'secured to the lower die bed 15. Said source" 28 may be any of several specific devices, such as a hydraulic motor, an electric motor, or an air or steam engine or motor.

Said bearing supports 26 and 25 are substantially mirror images of each other. Therefore, the leftward bearing support 25 will be described in detail and such description will be understood to refer to both supports.

The bearing support 25 has a horizontal bedplate 31, mounted upon the lower die bed 15, and a vertical hearing plate 32 (Figures 3, 6 and 7) secured to said bed plate 31 along the leftward edge thereof. The bearing 23 is supported in said vertical plate 32 in the lower portion thereof midway between the front and rear edges thereof. A circular opening (Figure 7), whose axis is parallel with the axis of said bearing 23, is provided through said vertical plate 32 directly above said bearing 23. The rightward or inner face of the vertical plate 32 is provided with a recess 33 (Figure 6) which extends from the top of said vertical plate to a horizontal line near the lower edge thereof and also extends between two parallel, vertical lines near the frontand rear edges thereof. A pair of vertical guides 34 and 35 are secured in said recess near the front and rear edges thereof on opposite sides of, and spaced from, said opening 30, as shown in Figures 3and 6. A slide 36 is vertically, slidably disposed between the vertical guides 34 and 35 and supports a bearing (Figure 7) which, in one position of said slide 36, is substantially co-axial with the circular opening 30 in the vertical plate 32.

operatingposition, the arms of said levers 49 and51 extend upwardly and outwardly from the center of the mechanism 10, as shown in Figure 2. The pivoted ends of the levers 49 and 51 are each provided with a cam surface 53 engaged by the cam plate 46. Downward movement of the outer ends of the levers, operating through the brackets 47 and 48, and the slides 36 and 39, effects an upward movement of the upper roll 22. Said levers The leftward end of the upper roll 22 is rotatably supported in the bearing 37 and extends therebeyond through the circular opening 30, which is slightly larger than the portion of said upper roll extending therethrough. Thus,

said upper roll can be moved slightly in a radial direction within said opening 30. The rightward end of the upper roll 22 is rotatably supported in a bearing 38 mounted in a slide 39 which is slidably supported on the leftward face of the bearing support 26 in substantially the same manner as hereinabove described with respect to the slide 36. The upper and lower rolls 22 and 21, respectively, are interconnected by the gears 41 and 42 mounted upon the leftward ends of said rolls beyond the vertical plate 32.

Shaft seals 43 and 44 are provided around the leftward ends of said upper and lower rolls in a conventional manner between said gears 41 and 42 andthe vertical plate 32.

The upper edges of the vertical plates 32 of the hearing supports 25 and 26 are both recessed, as at 45 in Figure 9, midway between the front and rear edges thereof. A removable cam plate'46 is disposed within said recess 45. Lever brackets 47 and 48 (Figure 2) are secured to the upper edge of the slides 36 and 39, respectively, midway between their vertical edges, and extend outwardly over the cam plates 46 on their respective adjacent bearing supports. Actuating levers 49 and 51, which in this embodiment are bifurcated at one end of each, are pivotally supported at saidone end upon the lever brackets 47 and 48, respectively, by means of pins 52.- In normal.

are engageable at their outer ends by adjustment bolts 54 and 55, respectively, mounted upon actuation arms 56 and 57 secured to the upper die bed 12 (Figures 1 and 2). A ratchet wheel 58 is mountedupon the rightward end of the lower roll 21 externally of the bearing support 26 (Figures 2, 4, 5 and 8). Said ratchet wheel 58 is provided with two diametrically opposite teeth 60, in this particular embodiment, engageable by an edge of the pawl 59 near one end thereof. The other end of said pawl is pivotally supported upon the pawl bracket 61, for movement about avertical axis. As shown in Figure 8, the side of the pawl 59 opposite that engaged by the ratchet wheel 58 is resiliently backed by the spring 62 which is supported by means fixed with respect to the bearing support 26. Thus, the spring 62 normally urges the pawl 59 against the edge ofthe ratchet wheel 58.

The pawl 59 is engaged by a pawl cam 63 along the same edge as that engaged by the ratchet wheel 58 and.

adjacent thereto. Said pawl cam 63* is mounted upon the lower end of a cam rod 64 (Figures 2 and 4) which is pivotally secured at its upper end. to a crank wheel 65 near the periphery thereof. Said crank wheel 65 is mounted upon a shaft 66 which is rotated in positive relation with the operation of the dies. In this particular embodiment, the shaft 66 is rotated on a one to one ratio by the extension of the crank shaft 13 in the punch press head 14 (Figures 2 and 4). Said crank shaft 13 and the shaft 66 are here interconnected by a pair of bevel gears 67 but other driving arrangements will be apparent. The

cam rod'64 is slidably embraced intermediate its ends by the pivot block 68 whichis rotatably supported upon the pivot bracket 69, which may be secured for convenience to the punch press head frame 14.

Accordingly, as shown in Figures 2 and 5, the rotation of the crank wheel 65 in one direction, here a counterclockwise direction as shown in Figure 2 effects an oppositerotation, here a clockwise rotation, of the pawl oam '63"approximately about the point X on the ratchet engaging side of the pawl 59 (Figure 2). The pawl cam 63 has a low dwell surface 76 (Figure 4) which is sufficiently spaced from the high dwell surface 75 on the pawl 59 that there will be no interference between the pawl cam 63 and the pawl 59 when said cam 63 is moved from the broken line position 77 (Figure 5) to the solid line position shown therein. As the cam 63 is then moved upwardly, its beveled cam surface 72 engages a corresponding beveled cam surface 73 (Figure 4) on the pawl 59 thereby moving said pawl 59 away from the ratchet wheel 58. After the cammed surfaces have completed their engagement, the high dwell surface 74 on the cam 63 momentarily engages thehigh dwell surface 75 on the pawl 59. The cnank wheel 65 is of sufficient diameter to effect movement of the pawl cam 63'completely above the pawl 59 during a portion of its movement about the point X, thereby releasing engagement between the high dwell surfaces of the pawl cam 63 and the pawl 59, after which said pawl 59 re-engages' the periphery of the ratchet wheel 58.

As shown in Figure 7, the upper roll 22 may be relieved as at 78,to prevent interference thereby with any distortions in the stock being worked upon by the press asa result ofthe operation effected by said press. The horizontal platform '79' (Figure 3) has two substantially coplanar sections disposed upon opposite sides of the'rolls 21 'and'22. The upper surface of said platform preferably defines a' plane tangent to the upper surface of the lower roll 21.

Operation Referring first to Figures 1 and 2, the sheet stock 16 enters the front end of the punch press 11, passes through the dies 17 and 18, moves onto the platform 79 and then passes through the feed mechanism 10. As soon as the leading edge of said sheet stock is engaged between the upper and lower rolls 22 and 21, said feed mechanism moves the sheet stock through its entire cycle of operations until it is cut to size by the shear 19, on the opposite side of the feed mechanism 10 from the dies 17 and 18.

Sheet, ribbon or bar stock of considerable length may be, and preferably is, used with my feed'rnechanism 10 to take full advantage of the completely automatic operation after the leading edge of the stock is engaged between the rolls 21 and 22. Thus, Where hand feeding of a roll or very long length of sheet stock would be highly impractical if not impossible, the feed mechanism 10 openates efiiciently. The feed mechanism 10 is far more satisfactory than manual feeding, even with short lengths of sheet stock, particularly if said mechanism 10 is disposed ahead of the dies 17 and 18. However, even if said mechanism 10 operates in the position here shown, it still eliminates the danger created by manual feeding as the tnailing edge of a relatively short sheet or strip of stock approaches the dies 17 and 18.

The cycle of operation of the punch press in conjunction with the feed mechanism 10 can best be illustrated by starting with the upper die 17 in the raised position. At such time the actuating levers 49 and 51 are also in their raised position (Figures 2 and 9) and the rolls 21 and 2.2 are being driven counter-rotationwise by the motor 28 and the gears 41 and 42, thereby advancing the stock through the press. At this same time, the pawl cam 63 is in the dotted line position 77 (Figure 5) which is approximately 180 degrees in its rotational path from the solid line position 63 which is the same as its position shown in Figure 2, in which position the pawl 59 is in engagement with the periphery of the ratchet wheel 58 between the teeth thereon.

As the upper die is moved downwardly toward the lower die, continuing rotation of the ratchet 58 will presently cause the next of the teeth 60 to engage the pawl 59 and thereby stop the rotation of both rolls immediately and at a precisely controllable point. However, the source 28 of torque continues to apply torque undiminished and this will be available to commence an immediate restarting of the rolls as soon as the pawl 59 is withdnawn from its position of engagement with the ratchet. As the dies are about to engage, and after the stopping of the rolls by the pawl and ratchet mechanism, the adjustment bolts 54 and 55 come into engagement with, and then depress, the outer ends of the actuating levers 49 and 51. Such depression of said levers, operating through the cammed surfaces 53 thereof, effects a raising of the slides 36 and 39, thereby lifting the upper roll 22 a distance above the lower roll 21 suflicient to release the grip of said rolls upon the stock 16 therebetween. The openings 3i) (Figure 7) in the vertical plates 32 of the bearing supports 25 and 2.6 are sufiiciently large to permit such slight upward movement of the upper roll 22 with respect to the lower roll 21. Thus, normal action of the stock aligning means (not shown) is permitted just before the upper and lower dies mesh with each other and after movement of the work has ceased.

During the downward movement of the upper die 17, the pawl cam 63 moves from the broken line position 7'7 in Figure 5 to the solid line position shown in Figures 4 and 5. When the upper die moves away from the lower die, the adjustment bolts 54 and 55 will likewise be moved away from the actuating levers 49 and 51 thereby permitting the upper roll 22 to be lowered by the slides 36 and 32 back into engagement with the sheet stock 16. Immediately thereafter, and after the sheet stock is stripped from said dies, the cammed surface 72 (Figure 4) of the cam 63 first engages the cammed surface 73 of thepawl 59. The high dwell surface 74 of the cam 63 then engages the high dwell surface 75 of the pawl 59, thereby backing the pawl 59 away from the ratchet Wheel 58. The ratchet Wheel, hence the rolls 21 and 22, begin immediately to rotate again, the source of constant torque 28 having been under continuous application during this period. The movement of the pawl cam 63 is coordinated and timed with the movement of the upper die bed 12. After a momentary disengagement between the pawl and the ratchet wheel, the pawl cam 63 moves above said pawl 59 thereby permitting said pawl to re-engage the periphery of the ratchet wheel 58. However, since the tooth previously engaged by said pawl has now passed the position where said pawl can engage same, the ratchet wheel continues to rotate with the pawl sliding along the periphery thereof, until the next tooth 60 is engaged.

In this particular embodiment, the upper die makes a complete cycle from lowered position to raised position and back to lowered position during each half rotation of the ratchet wheel 58 and, therefore, between each engagement with a tooth on the ratchet wheel 58 by the pawl 59. More or less teeth may be provided on the wheel 58 depending upon the distance which it is desired that the sheet stock should be moved between operating cycles of the punch press.

When the high dwell surfaces of the pawl 59 and pawl cam 63 are engaged, the spring 62 (Figure 8) will be under increased compression.

The application of constant torque to the rolls 21 and 22 insures their immediate and positive movement upon removal of the pawl 59 from engagement with teeth 60 of the ratchet 58. Thus, although the rolls 21 and 22 are caused to separate slightly just before and during the engagement of the dies, this is solely to permit the aligning means (not shown) of the dies to engage the work and align it in the usual manner. Such aligning means may, for example, be any form of conventional tapered aligning pins which in a known manner engage the work immediately after the release of the driving rollers and effect a positive alignment thereof with the die parts. Separation of the driving rollers is, of course, necessary in order to permit the aligning pins to shift the Work if it is out of its proper position. The separation and re-engagement of the rolls is not relied upon to stop and start progression of the work from one station to the next, but rather such stop and start is effected by the action of the pawl 59 against the ratchetv 58 on the one hand and the constant torque source on the other.

Changes to accommodate different thicknesses of stock are readily made by merely adjusting the screws 54 and 55 (Figure 1) and this will not alter the feeding timing. Similarly, changes in feeding timing may be made by changing the ratchet 58, the cam 63 and the linkage operating the cam 63, but these changes will not necessarily affect the adjustment of the mechanism for sheet thickness. Further, the mechanism can be readily adjusted to effect feeding at any desired point in the die operating cycle.

It will be recognized that modifications in the sizes of, and reliefs in, the upper and/or lower rolls, the size and shape of the ratchet wheel 58 or similar modifications in the specific structure of the feed mechanism 10 may be made without departing from the scope of this invention. Therefore, although a particular, preferred embodiment of my invention has been described and disclosed herein, it will be understood that modifications thereof within the scope of such disclosure are fully contemplated wtihin this application unless specifically stated to the contrary in the appended claims.

I claim:

1. A blocking device comprising in combination: a

coaxial with, said roll; a pawl mounted for movement into and out of contact with the periphery of said ratchet wheel; a rod having a cam surface thereon engageable with said pawl for causing movement thereof into and out of engagement with said ratchet wheel; a power source; means connecting said rod to 'said' power source for sequentially moving said cam surface into and out of engagement with said pawl.

2. The combination of claim 1, wherein said pawl has a cam surface thereon; means pivotally mounting said rod intermediate its ends, for moving said rod cam surface through a closed arcuate path in a plane parallel with the axis of said roll, said cam surface on said rod engaging the cam surface on said pawl during a portion of its arcuate movement.

3. In a mechanism for advancing sheet stock between the dies of a press, the combination comprising: a pair of parallel, adjacent rolls for normally engaging said sheet stock; means rotatably supporting said rolls, one of said rolls being radially movable with respect to the other roll; a source of constant torque connected to one of said rolls for continuously urging same to rotate in one direction; means for rotating the other roll in the opposite direction; a power source for said press; blocking means for sequentially engaging one of said feeding rolls and preventing rotation thereof; means connecting said power source to said blocking means for causing sequential operation of said blocking means in timed relationship with the operation of the press.

4. A device for feeding elongated stock to and through a treating apparatus, including the combination: a pair of parallel, tangentially adjacent, feeding rolls for engaging said stock and feeding same; gearing interconnecting said rolls for causing simultaneous, but opposite, rotation thereof; a source of constant torque connected to one of said rolls at one end thereof for continuously urging said one of said rolls to rotate in one direction; a power source for operating said treating apparatus, said power source having a rotatable shaft; a movable blocking member for sequentially engaging said one of said rolls and preventing rotation thereof; means connecting said rotatable shaft to said blocking member for causing sequential movement of said blocking member in response to rotation of said shaft; mounting means for the other of said rolls, said mounting means permitting radial movement of said other roll toward and away from said one roll; means operable by said power source for moving said other roll toward and away from said one roll in timed relationship to the movement of said blocking member.

5. A device for feeding elongated stock to and through a treating apparatus, including the combination: a pair 1 of parallel, tangentially adjacent feeding rolls for engaging said stock and feeding same; gearing interconnecting said rolls for causing simultaneous, but opposite, rotation thereof; a source of constant torque connected to one of said rolls at one end thereof for continuously urging said one of said rolls to rotate in one direction; a toothed ratchet wheel secured to, and coaxial with, said one roll at the other end thereof; a power source for operating said treating apparatus, said power source having a rotatable shaft; a movable blocking member for sequentially engaging said one of said rolls and preventing rotation thereof, said blocking member including a pawl mounted for movement into and out of contact with said ratchet wheel; a rod having a cam surface thereon engageable with said pawl for causing movement thereof into and outof engagement with said ratchet wheel; means connecting said rod to said shaft for sequentially moving said cam surface into and out of engagement with said pawl.

6. A device for feeding elongated sheet stock to and through the dies of a press, including: a pair of rotatable,

tangentially adjacent feeding rolls for engaging said stock and feeding same, the axes of rotation of said rolls lying in parallel planes; means rotatably supporting said rolls, one of said rolls being radially movable with respect to the other roll; a source of constantly applied torque connected to said' other roll for continuously urging same to rotate in one direction; means for rotating said means connecting said power source to said blocking means for causing sequential operation of said blocking means in timed relationship with the operation of the press. I

7. A device according to claim 6 including means operable by said power source for moving said one roll toward and away from said other roll in timed relationship to the movement of said blocking member.

8. A device for feeding elongated sheet stock, to and through the dies of a press including: a pair of rotatable, tangentially adjacent feeding rolls for engaging said stock and feeding same, the axes of rotation of said rolls lying in parallel planes; gearing interconnecting said rolls for causing simultaneous, but opposite, rotation thereof; a source of constantly applied torque connected to one of said rolls at one end thereof for continuously urging said one of said rolls to rotate in one direction; a power source for said press; blocking means sequentially movable into and out of engagement with said one feeding roll for sequentially blocking and permitting rotation thereof; means connecting said power source to said blocking means for causing sequential operation of said blocking means in'timed relationship with the operation of the press.

9. A device for feeding elongated sheet to and through the dies of a press, including: a pair of parallel, tangentially adjacent rolls for normally engaging said sheet stock; means rotatably supporting said rolls, one of said rolls being radially movable with respect to the other roll; a source of constantly applied torque connected to said other roll for continuously urging same to rotate in one direction; means for rotating said one roll in the opposite direction; a power source for said press; blocking means sequentially movable into and out of engagement with said other feeding roll for sequentially blocking and permitting rotation thereof, said blocking means including a ratchet wheel on said other roll and a pawl mounted for movement into and out of contact with said ratchet wheel; means connecting said power source for causing movement of said pawl into and out of contact with said ratchet wheel in timed relationship with the operation of the press.

10. A device for feeding elongated sheet stock through the dies of a press, including: a pair of parallel, adjacent rolls for normally engaging said stock and feeding same; means rotatably supporting said rolls, one of said rolls being radially movable with respect to the other roll; a source of constantly applied torque connected to the other of said rolls for continuously urging same to rotate in one direction; means for rotating said one roll in the opposite direction; a power source for said press; blocking means for sequentially engaging said other roll and preventing rotation thereof; cam means engageable with said blocking means for causing operation thereof; and means connecting said cam means to said power source for causing sequential operation of said blocking means in timed relationship with the operation of the press.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Mundell et a1. Nov. 14, 1882 Kent May 13, 1919 Graham Feb. 19, 1924 Hugo Nov. 8, 1927 Crane Mar. 29, 1932 Crane June 25, 1935 10 Booth Oct. 10, 1939 Miller et a1 Mar. 30, 1942 Schefiey July 4, 1950 Clutz Feb. 13, 1951 Baumgartner May 19, 1953 Kenworthy et a1 Nov. 2, 1954 Klasing Feb. 1. 1955 

